Abstract:
Improved fin field effect transistor (FinFET) devices and methods for fabrication thereof. In one aspect, a method for fabricating a FinFET device comprises: a silicon substrate on which a silicon epitaxial layer is grown is provided. Sacrificial structures on the substrate are formed from the epitaxial layer. A blanket silicon layer is formed over the sacrificial structures and exposed substrate portions, the blanket silicon layer having upper and lower portions of uniform thickness and intermediate portions interposed between the upper and lower portions of non-uniform thickness and having an angle of formation. An array of semiconducting fins is formed from the blanket silicon layer and a non-conformal layer formed over the blanket layer. The sacrificial structures are removed and the resulting void filled with isolation structures under the channel regions. Source and drain are formed in the source/drain regions during a fin merge of the FinFET.
Abstract:
An improved transistor with channel epitaxial silicon. In one aspect, a method of fabrication includes: forming a gate stack structure on an epitaxial silicon region disposed on a substrate, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; and growing a raised epitaxial source and drain from the substrate, the raised epitaxial source and drain in contact with the epitaxial silicon region and the gate stack structure. For a SRAM device, further: removing an epitaxial layer in contact with the silicon substrate and the raised source and drain and to which the epitaxial silicon region is coupled leaving a space above the silicon substrate and under the raised epitaxial source and drain; and filling the space with an insulating layer and isolating the raised epitaxial source and drain and a channel of the transistor from the silicon substrate.
Abstract:
A method of making a semiconductor device includes forming a fin mask layer on a semiconductor layer, forming a dummy gate over the fin mask layer, and forming source and drain regions on opposite sides of the dummy gate. The dummy gate is removed and the underlying fin mask layer is used to define a plurality of fins in the semiconductor layer. A gate is formed over the plurality of fins.
Abstract:
A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.
Abstract:
On a first semiconductor material substrate, an overlying sacrificial layer formed of a second semiconductor material is deposited. In a first region, a first semiconductor material region is formed over the sacrificial layer. In a second region, a second semiconductor material region is formed over the sacrificial layer. The first semiconductor material region is patterned to define a first FinFET fin. The second semiconductor material region is patterned to define a second FinFET fin. The fins are each covered with a cap and sidewall spacer. The sacrificial layer formed of the second semiconductor material is then selectively removed to form an opening below each of the first and second FinFET fins (with those fins being supported by the sidewall spacers). The openings below each of the fins are then filled with a dielectric material that serves to isolate the semiconductive materials of the fins from the substrate.
Abstract:
A shallow trench is formed to extend into a handle substrate of a semiconductor-on-insulator (SOI) layer. A dielectric liner stack of a dielectric metal oxide layer and a silicon nitride layer is formed in the shallow trench, followed by deposition of a shallow trench isolation fill portion. The dielectric liner stack is removed from above a top surface of a top semiconductor portion, followed by removal of a silicon nitride pad layer and an upper vertical portion of the dielectric metal oxide layer. A divot laterally surrounding a stack of a top semiconductor portion and a buried insulator portion is filled with a silicon nitride portion. Gate structures and source/drain structures are subsequently formed. The silicon nitride portion or the dielectric metal oxide layer functions as a stopping layer during formation of source/drain contact via holes, thereby preventing electrical shorts between source/drain contact via structures and the handle substrate.
Abstract:
A method of making a semiconductor device includes forming an intermediate structure including second semiconductor fin portions above a first semiconductor layer, and top first semiconductor fin portions extending from respective ones of the second semiconductor fin portions. The second semiconductor fin portions are selectively etchable with respect to the top first semiconductor fin portions. A dummy gate is on the intermediate structure. The second semiconductor fin portions are selectively etched to define bottom openings under respective ones of the top first semiconductor fin portions. The bottom openings are filled with a dielectric material.
Abstract:
An improved transistor with channel epitaxial silicon and methods for fabrication thereof. In one aspect, a method for fabricating a transistor includes: forming a gate stack structure on an epitaxial silicon region, a width dimension of the epitaxial silicon region approximating a width dimension of the gate stack structure; encapsulating the epitaxial silicon region under the gate stack structure with sacrificial spacers formed on both sides of the gate stack structure and the epitaxial silicon region; forming a channel of the transistor having a width dimension that approximates that of the epitaxial silicon region and the gate stack structure, the epitaxial silicon region and the gate stack structure formed on the channel of the transistor; removing the sacrificial spacers; and growing a raised epitaxial source and drain from the silicon substrate, with portions of the raised epitaxial source and drain in contact with the epitaxial silicon region.
Abstract:
Insulating layers can be formed over a semiconductor device region and etched in a manner that substantially reduces or prevents the amount of etching of the underlying channel region. A first insulating layer can be formed over a gate region and a semiconductor device region. A second insulating layer can be formed over the first insulating layer. A third insulating layer can be formed over the second insulating layer. A portion of the third insulating layer can be etched using a first etching process. A portion of the first and second insulating layers beneath the etched portion of the third insulating layer can be etched using at least a second etching process different from the first etching process.
Abstract:
The presence of a facet or a void in an epitaxially grown crystal indicates that crystal growth has been interrupted by defects or by certain material boundaries. Faceting can be suppressed during epitaxial growth of silicon compounds that form source and drain regions of strained silicon transistors. It has been observed that faceting can occur when epitaxial layers of certain silicon compounds are grown adjacent to an oxide boundary, but faceting does not occur when the epitaxial layer is grown adjacent to a silicon boundary or adjacent to a nitride boundary. Because epitaxial growth of silicon compounds is often necessary in the vicinity of isolation trenches that are filled with oxide, techniques for suppression of faceting in these areas are of particular interest. One such technique, presented herein, is to line the isolation trenches with SiN to provide a barrier between the oxide and the region in which epitaxial growth is intended.